mu3: coin input added

dist/mu3/segatools.ini

@@ -1,11 +1,11 @@
 [vfs]
 ; Insert the path to the game AMFS directory here (contains ICF1 and ICF2)
-amfs=amfs
+amfs=
 ; Create an empty directory somewhere and insert the path here.
 ; This directory may be shared between multiple SEGA games.
 ; NOTE: This has nothing to do with Windows %APPDATA%.
-appdata=appdata
-option=option
+appdata=
+option=
 
 [dns]
 ; Insert the hostname or IP address of the server you wish to use here.
@@ -40,8 +40,12 @@ enable=1
 ; Set "1" to use a xinput gamepad and set "2" to use keyboard.
 mode=2
 
+; Test button virtual-key code. Default is the 1 key.
 test=0x31
+; Service button virtual-key code. Default is the 2 key.
 service=0x32
+; Keyboard button to increment coin counter. Default is the 3 key.
+coin=0x33
 
 [dinput]
 LEFT_A=0x53